    ul{
        list-style: none;
        width: 300px;
        border: 2px solid #000000;
        margin: 100px auto;
        padding: 0;
        display:block;
        text-align: center;
    }
    li{
        border: 1px solid #1A66B3;
        background-color: #6b995e;
    }
    span{
        border:1px solid #cccccc;
        display:block;
        width: 100%;
        cursor: pointer;
    }
    div{
        background-color: #00B0E7;
        height: 100px;
        border:1px solid #110fff;
        display: none;
    }